Transketolase Is Identified as a Target of Herbicidal Substance α-Terthienyl by Proteomics.

-terthienyl is a natural phytotoxin isolated originally from (L.) Kuntze. The bioassay presented here shows the strong herbicidal activity of -terthienyl on , and . The -terthienyl-induced response of at the protein level was analyzed at different times. Changes in the protein expression profiles were analyzed by two-dimensional gel electrophoresis and liquid chromatography tandem mass spectrometry (LC-MS/MS) mass spectrometry. Sixteen protein spots were identified that showed reproducible changes in the expression of at least 2-fold when compared to the control. Among these 16 spots, three were up-regulated and 13 were down-regulated. The decreased expression of several proteins associated with energy production and carbon metabolism suggested that these processes were affected by -terthienyl. To search for the candidate proteins in this screen, T-DNA mutants of the candidate proteins were used to test their susceptibility to -terthienyl. Amongst the others, , a mutant of transketolase, exhibited a significantly lower sensitivity to -terthienyl when hit compared with Col-0. Based on the identification of the proteins associated with the response to -terthienyl by proteomics, a candidate target protein transketolase was identified.